Grinding wheel and lubricant arrangement

ABSTRACT

A GRINDING WHEEL ASSEMBLY IS PROVIDED WITH A PLURALITY OF INDIVIDUAL LUBRICATING CHAMBERS WHICH SUPPLY A FLUID LUBRICANT TO THE GRINDING SURFACE OF A GRINDING DISC DURING A GRINDING OPERATION. THE LUBRICATING CHAMBERS ARE FORMED BY A PLURALITY OF WEDGE-SHAPED RIBS ON A SUPPORT PLATE COOPERATING WITH A PLURALITY OF WEDGE-SHAPED PROJECTIONS ON A GRINDING PLATE AND DURING ROTATION OF THE GRINDING WHEEL, THE FLUID LUBRICANT IS CENTRIFUGED TO THE GRINDING SURFACE THROUGH HOLES IN THE GRINDING DISC IN FLUID COMMUNICATION WITH THE LUBRICATING CHAMBERS.

Sept. 21, 1971 H. JUILLERAT 3,606,710

GRINDING WHEEL AND LUBRICANT ARRANGEMENT Original Filed July 14, 1967 T 2 Sheets-Sheet 1 a .rd)

1w I 1 km I Sept 1, 1971 H. JUILLERIT 3,606,710

GRINDING WHEEL AND LuBRIcANE ARRANGEMENT Original Filed July 14, 1967 2 Sheets-Sheet 2 United States Patent 01 free 3,606,710 Patented Sept. 21, 1971 3,606,710 GRINDING WHEEL AND LUBRICANT ARRANGEMENT Henri Juillerat, 9 Rue du Chanet, 2014 Bole, Switzerland Continuation of application Ser. No. 653,557, July 14, 1967. This application May 11, 1970, Ser. No. 37,401 Claims priority, application Switzerland, July 26, 1966,

10,803/ 66 Int. Cl. B24b 55/02 US. Cl. 51356 Claims ABSTRACT OF THE DISCLOSURE A grinding wheel assembly is provided with a plurality of individual lubricating chambers which supply a fluid lubricant to the grinding surface of a grinding disc during a grinding operation. The lubricating chambers are formed by a plurality of wedge-shaped ribs on a support plate cooperating with a plurality of wedge-shaped projections on a grinding plate and during rotation of the grinding wheel, the fluid lubricant is centrifuged to the grinding surface through holes in the grinding disc in fluid communication with the lubricating chambers.

This is a continuation of Ser. No. 653,557, filed July 14, 1967, now abandoned.

By experimentation, it has been shown that a correctly lubricated grinding wheel lasts from two to three times longer than a non-lubricated wheel. However, up to now conventional methods of lubricating grinding wheels have usually been effected by means of a nozzle which projects a lubricant on the grinding wheel at the point of contact of the object to be ground with the wheel. Un fortunately, the circumferential speed of the grinding surface causes an over-pressured zone on the grinding surface of the diamond part so that the lubricant is deflected and accordingly, no longer fulfills its purpose and instead becomes a simple cooling agent. Therefore lubrication of the contact point of the tool with the grinding wheel is inhibited and it is not possible to obtain a cleaner, more rapid, work rate nor is it possible to avoid a dirtying of the grinding wheel by conventional lubricating methods.

The present invention has for its objective to eliminate the above-mentioned disadvantages thereby ensuring a better performance and a longer service life for the grinding wheel.

The advantages of grinding wheels built in accordance with the present invention are:

(a) No risk of dirtying the grinding surface regardless of the ground material;

(b) The posibility of grinding with very little lubrication;

(0) The possibility of checking very accurately the grinding, even with considerable lubrication;

(d) The particles of the material to be ground are projected, with force, rearwardly by the lubricating liquid coming out of the openings made in the abrasive surface of the grinding wheel in such a way that the part of the piece to be ground in contact with the wheel always remains clean.

The grinding wheel of the present invention comprises an annular abrasive surface surrounding a central, hollow portion, and characterized by the fact that the surface has openings therein communicating with lubricating chambers provided in the body of the grinding wheel. The lubricating chambers communicate with the central hollow portion of the grinding wheel by lateral openings made in the vertical walls in such a way as to permit pressurized lubrication of the abrasive surface by centrifuging the lubricating oil deposited in the hollow portion through the chambers and the openings of the abrasive surface during the rotation of the grinding wheel.

The accompanying drawing represents by way of example one embodiment of the object of the invention.

FIG. 1 shows a cross-sectional view, partially exploded, of a diamond grinding wheel.

FIG. 2 shows a plan view of the base flange of the wheel.

FIG. 3 shows a plan view of the intermediate flange of the wheel.

FIG. 4 shows a plan view of the diamond crown of the grinding wheel.

The grinding wheel of the present invention comprises a wheel bearing flange or support plate 1 which has a central bore 2 which has a diameter equal to the diameter of the trussel on which the wheel must be mounted and a central cylindrical, hollow portion 6. When the grinding wheel assembly is to be used, a fluid lubricant is fed through the bore 2 into the hollow portion 6 and then the support plate I mounted on the trussel thereby preventing the flow of lubricant back out through the bore 2. Then when the grinding assembly is rotated, the lubricant is centrifuged radially outwardly, as described in more detail hereinafter. This hollow portion is circularly milled in order to have an annular recess or housing 3, the milling being made in such a way that there remains positioned on the inner edge of this housing wedge-shaped ribs 4. The wedge-shaped ribs 4 have two elongated sides in the shape of an arc of a circle and two obliquely directed sides interconnecting the two elongated sides. The obliquely shaped sides are directed obliquely in the direction of rotation of the wheel, as indicated by arrow F, this orientation being considered as parting from the center of the wheel and extending outwardly towards the exterior (FIG. 2).

The grinding wheel also comprises a flange or grinding member 8 (FIG. 3) constituted by a crown 9 machined in such a way as to have Wedge shaped projections 10 disposed circularly thereon. These projections, equal in number to the number of wedge-shaped ribs 4 on flange 1, have a configuration somewhat similar to that of the ribs 4 and have two obliquely directed sides 11 and 12, these sides being oriented in the same way as those of flange 1, in the sense of rotation F of the wheel. The crown 9 is also provided with rectangular, oblique holes 13 located near each of faces 12. The wedge-shaped projections 10 extend in the housing 3 of flange 1 and cooperate with the wedge-shaped ribs 4 to define a plurality of individual lubricating chambers. The lubricating chambers communicate on the one hand with the hollow 6 of flange 1 via the openings 5 and on the other hand with the other face of the crown 9 via openings 13. The position of the wedge-shaped ribs 4 relative to the wedge-shaped projections 10 is indicated in dotted lines on FIG. 3.

A diamond crown or grinding disc 14 (FIG. 4), forming the abrasive surface of the wheel, is glued on the planar surface of crown 9. This diamond crown has rectangular holes 15 having a dimension corresponding to that of the holes 13 of the grinding member or flange 8 and disposed in the same manner as the latter, the diamond crown being secured in such a way that openings 15 coincide exactly with the openings 13.

The diamond crown can be made in any known manner, for example with resin binders, with Bakelite, or with metals melting at relatively low temperatures. It can also be cast, pressed or centrifuged. The entrance 5 of the lubricating chambers defined by the flanges 1 and 8 are machined to be biased together in the direction of rotation, i.e., the ribs 4 are forced into engagement with the projections 10 when the grinding wheel is rotated in the direction of the arrow F. During rotation of the grinding whel, the lubricant contained in the hollow 6 centrifuged or forced radially outward and sprayed through the openings 13-15 to the operative surface of the grinding Wheel.

The zone of over-pressure existing n the face of the grinding wheel due to the circumferential speed of the wheel and the resulting effect of which is harmful in the case of a conventional lubrication here has a positive effect, laminating laterally the liquid emerging from the openings against the diamond surface.

The dirtying of the grinding wheel becomes impossible and lubrication is guaranteed at the point of contact of the tool to be ground and at the points of the diamond.

The diamond points no longer heat up and accordingly remain sharp much longer than with a conventional grinding wheel.

Extensive checking has revealed a clear improvement in the cutting and in particular, an absence of rough spots on the angles of tools or of the materials milled.

It has also been noted that by employing a grinding wheel with a larger grain, more efficient results and better service can be obtained than with a conventional grinding wheel having a finer grain.

An important factor in the duration of a grinding wheel, such as above described, resides in the fact that the pressure exerted against the grinding wheel can be.

very small.

The positioning of the openings 15 has been adopted in order to grind without the danger of harming the grinding wheel on a sharp edge of a tool.

The invention has been disclosed with respect to a diamond plane grinding wheel but it is obvious that the lubricating arrangement can be applied to any other type of grinding wheel, in particular to conical or cylindrical grinding wheels. The abrasive used also can be other than diamond.

What I claim and desire to secure by Letters Patent is:

1. A grinding wheel assembly comprising: a support plate having therein means defining a recess and a plurality of ribs positioned in said recess in spaced-apart relationship; a grinding member having two opposed side faces; a grinding disc attached to one of said faces and a plurality of projections extending outwardly from the other of said faces into said recess and cooperative with respective ones of said ribs to define a plurality of lubricating chambers; means in said support plate receptive of a fluid lubricant for supplying same to said lubricating chambers; and means in said grinding member providing fluid communication between individual ones of said lubricating chambers and the grinding surface of said grinding disc for supplying fluid lubricant to said grinding disc surface during use of the grinding wheel.

2. A grinding wheel assembly according to claim 1; wherein said recess is circularly configured and said ribs are circularly spaced-apart around said recess; and wherein said other faces of said grinding member is circularly configured and said projections extend outwardly therefrom in circularly spaced-apart relationship.

3. A grinding wheel assembly according to claim 1; wherein each said rib is wedge-shaped and each said projection is complementarily wedge-shaped and abuts with respective ones of said wedge-shaped ribs to define said lubricating chambers.

4. A grinding wheel assembly according to claim 1; wherein said means in said support plate receptive of a fluid lubricant includes means defining a hollowed out portion in communication with each of said lubricating chambers, and means defining a bore extending axially through said support plate opening into said hollowed out portion.

5. A grinding wheel assembly according to claim 1; wherein said means in said grinding member for supplying fluid lubricant to said grinding disc surface comprises means defining a plurality of holes in said grinding disc surface, and means defining a plurality of holes axially extending through said grinding member providing fluid communication between respective ones of said lubricating chambers and first-mentioned holes.

References Cited UNITED STATES PATENTS 2,089,040 8/1937 Shue 51-267X 2,626,493 1/1953 Speicher 51267 3,041,799 7/1962 Kemman 51-267X 3.386.214 6/1968 Shoemaker 51----356 OTHELL M. SIMPSON, Primary Examiner 

